Its headline rating is a breaking capacity Icu of 55 kA at 415 V AC — that means it can safely interrupt a fault current up to 55,000 A without welding contacts or rupturing the case, which is the class M rating for the 3VA2 platform. The ETU350 offers adjustable overload protection Ir from 63 A to 160 A, short-time pickup Isd from 1.5 to 10 × Ir, and a fixed instantaneous pickup Ii at 10 × In. That LSI curve set lets you coordinate downstream breakers and still clear a hard fault fast — typical for feeder duty to motor control centers or sub-distribution boards.
Trip unit and auxiliary functions
This variant includes a shunt trip (STL) rated for 12–30 V DC and 24 V AC at 50/60 Hz. The shunt trip is what lets a remote signal — from an emergency-stop relay, a fire-alarm panel, or a PLC-driven safety contact — open the breaker without an operator at the handle. The 12–30 V DC range covers standard 24 V DC control supplies with margin. Connections are clamp-type (box lug), which accept a range of conductor sizes without needing compression lugs — common in panel building where termination speed and rework flexibility matter.
At 160 A frame size, it occupies three pole widths (roughly 105 mm) and needs clearance for the operating handle and arc-chute venting — standard for IEC molded-case breakers in distribution boards.